用粘塑性材料作为传力介质的板料半模成形技术

Sheet Metal Flexible Die Forming Technology by Using The Viscoplastic Carrying Pressure Medium

在传统的板料半模成形工艺中,所使用的传力介质为橡胶、聚胺脂、橡皮囊、油或水等,但它们都有各自的缺点。油或水容易泄漏,容框内压力难于进一步提高,尤其在成形失败时,液体飞溅不仅污染环境,而且累及操作者;橡皮囊成形机价格昂贵,且难以实现深拉延和深弯曲;而采用聚氨酯或橡胶做为软模时,还受到自身变形条件限制,难以成形局部变形量较大零件。基于此,作者探索性地进行了用粘塑性材料作为传力介质来进行板料成形的研究。通过大量实验,探索出了理想的粘塑性传力介质应具备的条件,并寻找到了一种合适的粘塑性传力介质。用这种介质,在同一容框内,通过更换不同凸模生产了五种不同的特形零件。实验表明,用该方法可使筒形件的拉延比达到0.38,最大变薄率小于10%,零件形状误差,表面质量均不低于充液拉延,甚至可以很方便地成形法兰与拉延方向不垂直的零件。

In this paper,an attempt is made in an exploratory way to discover a new process of sheet metal flexible die forming technology by using the viscoplastic carrying pressure medium (VCPM). After many experiments,conditions possessed by the medium have been decided;and the medium and its ingredients for the sheet metal flexible die forming have been explored,With the deep drawing forming of 08AL sheet metal by using the flexible die,deforming force,cavity pressure of the medium(medium pressure in cavity),blankholding force,the deforming velocity are determined,Meanwhile,the regular rules of their effects on the forming properties are studied. The better deformation conditions and the limit drawing ratio are also found.